Wiring connection method and wiring connection structure

ABSTRACT

A wiring connection method includes the steps of connecting a bus bar for wiring inside an electronic apparatus and a harness for leading out wiring to outside, placing the bus bar and the harness connected together on a notch portion of a housing, and filling a resin to fix the harness in the notch portion of the housing.

[0001] The present disclosure relates to the subject matter contained inJapanese Patent Application No.2001-178433 filed on Jun. 13, 2001, whichis incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a wiring connection method forleading out wiring of an electric circuit inside an electronic apparatusto the outside, and more particularly to a wiring connection method andstructure for a power wiring connection to which a large current isapplied.

[0004] 2. Description of the Related Art

[0005]FIG. 7 is an appearance view showing a wiring connection structureaccording to the related art for making wiring of an electronicapparatus to the outside. FIG. 8 is a cross-sectional view showing thewiring connection structure according to the related art for making thewiring of the electronic apparatus to the outside, taken along the lineA-A′ in FIG. 7.

[0006] Generally, the wiring connection method and structure accordingto the related art for leading out the electric circuit wiring insidethe electronic apparatus to the outside, particularly the power wiringconnection method and structure in which a large current is applied isconstructed so that a bus bar 4 and a connector pin 7 are insert moldedin a housing 5 for the electronic apparatus and the bus bar 4 isconnected via the soldered connector pin 7 to the outside, as shown inFIGS. 7 and 8.

[0007] As shown in FIGS. 7 and 8, in a wiring connection structure 70according to the related art for leading out wiring in the electronicapparatus to the outside, the bus bar 4 and the connector pin 7 areinsert molded in the case 5 molded of a resin material for the electriccircuit. The bus bar 4 is made of a metal material such as copper usefulto supply a large current. The connector pin 7 is made of metal materialsuch as copper and formed in L shape to lead out the electric circuitwiring to the outside. An electric circuit substrate portion 1 havingelectronic parts packaged on a printed board 2 (referred to as a board2) is mounted within the housing 5, in which the connector pin 7 and thebus bar 4, and the bus bar 4 and the land on the board 2 are soldered,respectively.

[0008] In this wiring connection, the wiring for the electric circuitsubstrate portion 1 composed of electric circuits including a controlcircuit is connected via the bus bar 4 and the connector pin 7 to apower supply wiring such as an external battery (connected to aconnector 9 a) and a load wiring (connected to a connector 9 b) by meansof a connector 8 for outside connection. Within this housing 5, theelectric circuit substrate portion 1 is mounted and after wiringconnection, a lid 6 molded of resin material is put on the housing 5,whereby the electronic apparatus is assembled.

[0009] The housing 5 is molded of resin material like a box, and has thebus bar 4 and the connector pin 7 insert molded. The electric circuitsubstrate portion 1 is mounted within the housing 5.

[0010] Projection ribs 5 c and 5 d are provided on the inner faces of afront frame portion and a rear frame portion for this housing 5,respectively. End portions 4 c and 4 d of the bus bar 4 are insertmolded into the projection ribs 5 c and 5 d. The electric circuitsubstrate portion 1 is mounted on the upper faces 5 e and 5 f of theprojection ribs 5 c and 5 d.

[0011] A projection portion 5 a having a concave portion 5 b with anopening at one end to insert the connector 8 for outside connection isprovided on an outer surface of the front frame portion for the housing5. The connector pin 7 is insert molded into a bottom wall 5 h of thisconcave portion 5 b. A rib 5 g for being attached the lid 6 made ofresin material to is molded on an upper face portion with an opening inthe housing 5. The connector 8 for outside connection is inserted intothe concave portion 5 b of the projection portion 5 a into which theconnector pin 7 for this housing 5 is insert molded. The electriccircuit wiring including a control circuit in the electric circuitsubstrate portion 1 mounted within the housing 5 is connected via theconnector pin 7 to the power source supply wiring connector 9 a for theexternal battery and the load wiring connector 9 b by means of theconnector 8 for outside connection.

[0012] The bus bar 4 has the terminals 4 a, 4 b formed by punching andbending a part of the bus bar 4 at positions spaced apart apredetermined distance from one end of the front face side toward therear face side (e.g., a junction position with the connector pin 7, anda junction position with a land of the board 2), the terminals 4 a and 4b being formed of a metal material such as copper like a plate. This busbar 4 has the end portions 4 c and 4 d insert molded into the projectionribs 5 c and 5 d provided on the front frame portion and the rear frameportion of the housing 5, respectively. This bus bar 4 connects thepower supply wiring via the connector pin 7 to the land on the board 2by soldering the terminal 4 a of the bus bar 4 with a junction portion71 of the connector pin 7 and soldering the terminal 4 b of the bus bar4 with a junction portion 72 of the board 2, after the electric circuitsubstrate portion 1 is mounted within the housing 5.

[0013] In the above wiring connection method and structure for leadingout the wiring inside the electronic apparatus to the outside,particularly the power wiring connection method and structure in which alarge current is applied, it is required to solder the bus bar and theconnector pin provided within the housing of the electronic apparatusand to solder the board and the bus bar. The soldering must be performedafter the bus bar, the connector pin, and the board are accommodatedwithin the housing, and takes a lot of trouble. Also, the connector isused for wiring connection, resulting in increase of costs.

SUMMARY OF THE INVENTION

[0014] The present invention has been achieved to solve theabove-mentioned problems. It is an object of the invention to provide awiring connection method and a wiring connection structure in which thewiring connection can be made in a smaller number of steps, and thecosts can be reduced.

[0015] In order to accomplish the above object, a first aspect of theinvention provides a wiring connection method having the steps ofconnecting a bus bar for wiring inside an electronic apparatus and aharness for leading out wiring to outside, placing the bus bar and theharness connected together on a notch portion of a housing, and fillinga resin to fix the harness in the notch portion of the housing.

[0016] A second aspect of the invention provides the wiring connectingmethod according to the first aspect, in which in the placing step, aconnection portion between the bus bar and the harness is placed in aportion to be filled with the resin.

[0017] A third aspect of the invention provides the wiring connectingmethod according to claim 1, in which in the filling step, a connectionportion between the bus bar and the harness is covered with the resin.

[0018] A fourth aspect of the invention provides the wiring connectingmethod according to the second aspect, further having the steps ofdisposing a heat sink to contact with a portion filled with the resin.

[0019] A fifth aspect of the invention provides the wiring connectingmethod according to the first aspect, further having the steps ofsoldering the bus bar with an electric circuit board.

[0020] A sixth aspect of the invention provides a wiring connectionmethod having the steps of connecting a bus bar for wiring inside anelectronic apparatus and a harness for leading out wiring to outside,placing the bus bar and the harness on a notch portion of a housing sothat a connecting portion between the bus bar and the harness is exposedoutside the housing, filling a resin to fix the bus bar in the notchportion of the housing to insert-mold the bus bar into the housing, andcovering the connection portion between the bus bar and the harnessexposed from the housing with a thermal conductive resin.

[0021] A seventh aspect of the invention provides a wiring connectionmethod having the steps of placing a bus bar on a notch portion of ahousing so that a top end portion of the bus bar for wiring inside anelectronic apparatus is exposed outside the housing, filling a resin tofix the bus bar in the notch portion of the housing to insert-mold thebus bar into the housing, connecting a harness with the bus bar at theoutside of the housing, and covering a connection portion between thebus bar and the harness exposed from the housing with a thermalconductive resin. The placing step is conducted prior to the connectingstep.

[0022] An eighth aspect of the invention provides a wiring connectionmethod for an electronic apparatus containing electronic parts requiringlarge current for driving, the method having the steps of integrallymolding a harness for wiring inside the electronic apparatus and leadingout wiring to outside of a housing with the housing at a time of moldingthe housing.

[0023] A ninth aspect of the invention provides the wiring connectionmethod according to the eighth aspect, further having the steps ofplacing the harness on a notch portion of the housing.

[0024] A tenth aspect of the invention provides a wiring connectionstructure for an electronic apparatus containing electronic partsrequiring large current for driving, the structure having a housing anda harness for wiring inside the electronic apparatus and leading outwiring to outside of the housing. The harness is molded integrally witha housing.

[0025] An eleventh aspect of the invention provides the wiringconnection structure according to the tenth aspect, in which a notchportion is formed in the housing, the harness passes through the notchportion from outside of the housing to inside thereof, and the harnesshas core wiring covered with a jacket.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026]FIG. 1 is an appearance view showing a wiring connection structurefor connecting wiring of an electronic apparatus to the outsideaccording to a first embodiment of the present invention.

[0027]FIG. 2 is a cross-sectional view showing a wiring connectionmethod for connecting the wiring of the electronic apparatus to theoutside according to the first embodiment-of the invention, taken alongline B-B′ in FIG. 1.

[0028]FIG. 3 is an explanatory cross-sectional view showing the steps ofa wiring connection method for connecting the wiring of the electronicapparatus to the outside according to the first embodiment of theinvention.

[0029]FIG. 4 is a cross-sectional view showing a wiring connectionstructure for connecting wiring of an electronic apparatus to theoutside according to a second embodiment of the invention.

[0030]FIG. 5 is an explanatory cross-sectional view showing the steps ofa wiring connection method for connecting the wiring of the electronicapparatus to the outside according to the second embodiment of theinvention.

[0031]FIG. 6 is a cross-sectional view showing a wiring connectionstructure for connecting the wiring of an electronic apparatus to theoutside according to a third embodiment of the invention.

[0032]FIG. 7 is an appearance view showing a wiring connection structureaccording to the related art for connecting the wiring of an electronicapparatus to the outside.

[0033]FIG. 8 is a cross-sectional view showing the wiring connectionstructure according to the related art for connecting the wiring of theelectronic apparatus to the outside, taken along line A-A′ in FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] The preferred embodiments of the present invention will bedescribed below with reference to the accompanying drawings.

[0035]FIG. 1 is an appearance view showing a wiring connection structurefor connecting wiring of an electronic apparatus to the outsideaccording to a first embodiment of the present invention. FIG. 2 is across-sectional view showing a wiring connection method for connectingthe wiring of the electronic apparatus to the outside according to thefirst embodiment of the invention, taken along line B-B′ in FIG. 1.Through the first to third embodiments, the same parts are designated bythe same or like numerals and description for these parts is givenmainly in the first embodiment and is omitted in other embodiments.

[0036] As shown in FIG. 1 and FIG. 2, the wiring connection structure 10for connecting the electronic apparatus to the outside according to thefirst embodiment of the invention, the wiring connection structure 10 isconstructed so that a bus bar 14 and a harness 17 for outside connectionare insert-molded into a housing 15 while the bus bar 14 and the harness17 are jointed. The bus bar 14 is made of a metal material such ascopper used to supply a large current. The harness 17 for outsideconnection is formed of a metal wire rod such as copper wire having ajacket made of an insulating material. The housing 15 is formed of aresin material for the electronic apparatus. An electric circuitsubstrate portion 11 having the electronic parts 13 packaged on aprinted board 12 (simply referred to as aboard 12) is mounted in thishousing 15. The bus bar 14 is soldered to the land of the board 12 towire. Whereby, the wiring of the electric circuit substrate portion 11having electric circuits including a control circuit is directlyconnected via the harness 17 for outside connection joined with the busbar 14 insert molded into the housing 15 to a power supply wiringportion 23 such as an external battery (e.g., connected to a connectoror a terminal portion of the battery) and a load wiring portion 24(e.g., a wiring portion on the board making up a load circuit or a loadcircuit connector) without using of any connector. After the electriccircuit substrate portion 11 is mounted in the housing 15 and is wiredand connected to the bus bar 14 insert-molded into the housing 15, thehousing 15 is covered with a lid 16 formed of a resin material. Wherebythe electronic apparatus of tightly closed structure is assembled.

[0037] The housing 15 is formed of resin material such as ABS resin likea box, in which the bus bar 14 and the harness 17 for outside connectionformed of a metal wire rod such as copper wire having a jacket made ofan insulating material, the harness 17 welded with the bus bar 14 areinsert molded into the housing 15. The electric circuit substrateportion 11 is mounted in the housing 15. The projection ribs 15 c and 15d are provided on the inner faces of a front frame portion and a rearframe portion of this housing 15, respectively. The end portions 14 cand 14 d of the bus bar 14 are insert molded into the projection ribs 15c and 15 d, respectively. The harness 17 for outside connection having ajacket 19 made of insulating material and a core wire 18 such as copperwire, the harness 17 welded with the bus bar 14 is disposed in anattaching hole 15 a provided on the front frame portion of the housing15. The harness 17 is insert molded into the housing 15 in a state wherethe harness 17 is joined with and connected to the bus bar 14.

[0038] The projection ribs 15 c and 15 d of this housing 15 are providedwith the planar portions 15 e and 15 f for mounting the electric circuitsubstrate portion 11. A rib 15 g for mounting the lid 16 made of a resinmaterial or the like is molded on an upper face portion with opening inthe housing 15.

[0039] After the electric circuit substrate portion 11 is mounted withinthe housing 15, the land of the board 12 is soldered with the bus bar14. Whereby, the electric circuit wiring of the electric circuitsubstrate portion 11 having electric circuits including a controlcircuit is directly connected via the bus bar 14 and the harness 17 foroutside connection to the power supply wiring portion 23 such as anexternal battery (e.g., connected to a connector or a terminal portionof the battery) and the load wiring portion 24 (e.g., a wiring portionon the board making up a load circuit or a load circuit connector).

[0040] Regarding insert molding the harness 17 for outside connectioninto the housing 15, in the case where the housing 15 is made of ABSmaterial, which is a resin material for low temperatures (e.g., 100°C.), the harness 17 for outside connection is disposed into theattaching hole 15 a on the front frame portion for the housing 15 and isinsert molded in a state where the jacket 19 of insulating materialcovers the core wire 18 such as copper wire. Also, in the case where thehousing 15 is made of TBS material, which is a resin material for hightemperatures (e.g., 220° C.) or PPS material (e.g., 300° C.), theharness 17 for outside connection is disposed into the attaching hole 15a on the front frame portion for the housing 15 and is insert molded ina state where a heat resisting taut tube 19 is put on the jacket 19 ofinsulating material, which covers the core wire 18 such as copper wire.When the ABS material is used, the above molding method may be used.

[0041] The bus bar 14 is formed with a bore 14 a for inserting andwelding the core wire 18 of the harness 17 for outside connection at aposition spaced apart a predetermined distance from one end of the frontface side toward the rear face side. The bus bar 14 also has a terminal14 b, which is formed by punching and bending a part of the bus bar 14at a position opposite to the land of the board 12. The bus bar 14 ismade of a metal material such as copper and shaped like a plate. Thisbus bar 14 has the end portions 14 c and 14 d-insert molded into theprojection ribs 15 c and 15 d provided on the front frame portion andthe rear frame portion of the housing 15, respectively. After theelectric circuit substrate portion 11 is mounted in the housing 15, theterminal 14 b of the bus bar 14 is inserted into a bore 12 b having theland of the board 12, and a connection portion 21 of the terminal 14 band the land of the board 12 are soldered, whereby the power supplywiring and the like are connected via the harness 17 for outsideconnection and the bus bar 14 to the land of the board 12.

[0042] The harness 17 for outside connection has the core wire 18 suchas copper wire covered with the jacket 19 of insulating material. Theharness 17 connects the wiring of the electric circuit substrate portion11 composed of electric circuits including a control circuit via the busbar 14 to the power supply wiring portion 23 such as an external batteryand the load wiring portion 24. The harness 17 is used to supply a largecurrent. This harness 17 for outside connection is welded beforehandwith the bus bar 14, whereby the electric circuit wiring of the electriccircuit substrate portion 11 are connected via the bus bar 14 to theexternal battery without using the connector. Hence, a current loss dueto the connector can be prevented when supplying large current.

[0043] Referring to FIG. 3, a procedure for the wiring connection methodof the wiring connection structure 10 for connecting the electronicapparatus to the outside will be described below.

[0044]FIG. 3 is an explanatory cross-sectional view showing the steps ofthe wiring connection method for connecting the wiring of the electronicapparatus to the outside according to the first embodiment of theinvention. FIG. 3A shows a step of welding the bus bar and the harness.FIG. 3B shows a step of placing the bus bar in the housing in a statewhere the bus bar and the harness are welded. FIG. 3C shows a step ofinsert molding the bus bar and the harness into the housing by fillingresin in the housing. FIG. 3D shows a step of mounting the electriccircuit substrate portion in the housing and soldering the bus bar withthe circuit pattern of the electric circuit substrate portion.

[0045] In the step of welding the bus bar 14 and the harness 17, severalharnesses 17 for outside connection having a predetermined length (e.g.,length from a position of the bus bar 14 provided in the electriccircuit substrate portion 11 including the control circuit to a positionof the power supply wiring portion 23 such as an external battery, or toa position of the load wiring portion 24) are connected with the bus barby ultrasonic welding or resistance welding, as shown in FIG. 3A. Inthis welding, the jacket 19 is removed by predetermined length and thecore wire 18 of the harness 17 for outside connection is inserted intothe bore 14 a provided in the bus bar 14 to project from a surface ofthe bus bar 14, and then the bus bar 14 and the core wire 18 a arewelded at a projection portion 22 of this core wire 18.

[0046] In the step of placing the bus bar 14 in the housing in a statewhere the bus bar 14 and the harness 17 are joined, the bus bar 14 andthe harness 17 welded are placed in the housing 15, as shown in FIG. 3B.This is performed by placing the end portion 14 d of the bus bar 14 in anotch portion 15 i of the projection rib 15 d provided in the rear frameportion of the housing 15, placing the front end portion 14 c of the busbar 14 in a notch portion 15 h of the projection rib 15 c provided inthe front frame portion of the housing 15, and placing the harness 17for outside connection in the attaching hole 15 a in the front frameportion of the housing 15 in a state where the jacket 19 covers the corewire 18.

[0047] Next, in the step of insert molding the bus bar 14 and theharness 17 into the housing 15 by filling resin into the housing, thebus bar 14 and the harness 17 are insert molded into the housing 15 byfilling resin in a placement portion of the housing 15 where the bus bar14 and the harness 17 are disposed, as shown in FIG. 3C. This isperformed by filling a resin material 26 in the end portion 14 d of thebus bar 14 disposed in the notch portion 15 i of the projection rib 15 dprovided in the rear frame portion of the housing 15, filling a resinmaterial 25 in the end portion 14 c of the bus bar 14 disposed in thenotch portion 15 h of the projection rib 15 c provided in the frontframe portion of the housing 15, and filling a resin material 27 in theharness 17 for outside connection disposed in the attaching hole 15 a inthe front frame portion of the housing 15.

[0048] Lastly, in the step of mounting the electric circuit substrateportion 11 in the housing 15 and soldering the bus bar 14 with thecircuit pattern of the electric circuit substrate portion 11, theelectric circuit substrate portion 11 is mounted on the upper faces 15 eand 15 f of the projection ribs 15 c and 15 d in the housing 15 havingthe bus bar 14 and the harness 17 for outside connection insert molded,as shown in FIG. 3D.

[0049] At the time of mounting the electric circuit substrate portion 11in the housing 15, the end portion 14 b of the bus bar 14 is insertedinto the bore 12 b having the land of the board 12, and the electriccircuit substrate portion 11 is attached on the housing 15, using anattaching screw (not shown) The projection portion 21 at the terminal 14b of the bus bar 14 inserted into the bore 12 b of the board 12 havingthe land and the land of the board 12 are soldered. This step ofsoldering the terminal 14 b of the bus bar 14 and the land of the board12 may be made at the time of joining the bus bar 14 and the harness 17for outside connection before placing-the bus bar 14 and the harness 17for outside connection in the housing 15.

[0050] An electronic apparatus of sealed structure, for example, isassembled by putting the lid 16 on the housing 15 in which the electriccircuit substrate portion 11 is mounted. The harness 17 for outsideconnection disposed in this electronic apparatus is connected to thepower supply wiring portion 23 such as an external battery (e.g.,connected to a connector 23 or a terminal portion of the battery) andthe load wiring portion 24 (e.g., a wiring portion on the board makingup a load circuit or a load circuit connector).

[0051] As described above, in the wiring connection method and wiringconnection structure 10 for connecting the electronic apparatus to theoutside according to the first embodiment of this invention, the bus bar14 used to supply a large current and the harness 17 for outsideconnection are welded before they are accommodated within the housing15, and insert molded into the housing 15 for the electronic apparatusin a state where they are joined. Whereby, the wiring of the electriccircuit substrate portion 11 having electric circuits including acontrol circuit, which is soldered to the bus bar 14, to the outside canbe directly connected via the harness 17 for outside connection to thepower supply wiring portion 23 such as an external battery and the loadwiring portion 24 without using any connector. Hence, number of partssuch as a connector can be reduced. Since the bus bar 14 and the harness17 for outside connection are joined before being accommodated withinthe housing 15, number of steps for soldering the connector pin and thebus bar can be reduced. It is possible to prevent a current loss due tothe connector when supplying a large current.

[0052] A wiring connection structure 30 for connecting an electronicapparatus to the outside according to a second embodiment of theinvention will be described below with reference to the accompanyingdrawings.

[0053]FIG. 4 is a cross-sectional view showing the wiring connectionstructure for connecting the wiring of the electronic apparatus to theoutside according to the second embodiment of the invention.

[0054] As shown in FIG. 4, in the wiring connection structure 30connecting for the electronic apparatus to the outside according to thesecond embodiment of the invention, for the first embodiment, one edge34 a of a bus bar 34 and one end 38 a of a core wire 38 of a harness 37for outside connection are welded. A welded connection portion betweenthe one edge 34 a and the end 38 a protrudes from a front frame portion35 a of housing 35. The bus bar 34 is made of a metal material such ascopper used to supply a large current and is formed in an L shaped. Theharness 37 for outside connection includes a metal wire rod such ascopper wire having a jacket made of an insulating material. The bus bar34 joined with the harness 37 for outside connection is insert moldedinto the housing 35. The welded connection portion between the one edge34 a of the bus bar 34 and the one end 38 a of the harness 37 foroutside connection is molded of a resin material 44 having a highthermal conductivity. Accordingly, only a different point from the firstembodiment of the invention will be described. The different pointincludes the welded connection portion between the bus bar 34 and theharness for outside connection, insert molding the bus bar 34 into thehousing 35, and injection molding the resin material 44 into the weldedconnection portion between the bus bar 34 and the harness 37 for outsideconnection. The description of other points is omitted.

[0055] The housing 35 is formed of resin material such as ABS, TBT orPPS resin and shaped like a box, in which the bus bar 34 with which theharness 37 for outside connection formed of a metal wire rod such ascopper wire having the jacket made of an insulating material is weldedis insert molded into the housing 35. On the rear face side of thishousing, a heat radiating plate 46 to which the electronic parts 45having large heat capacity are attached is installed. A lid 36 formed ofresin material is attached on the upper side of the housing 35.

[0056] The projection ribs 35 a and 35 b are provided on the inner facesof a front frame portion and a rear frame portion of this housing 35,respectively. A portion 34 d, which is apart from the one edge 34 a ofthe bus bar 34, is disposed in the projection rib 35 a in a state wherethe one edge 34 a at a front side of the bus bar formed in the L shapedprotrudes from the front frame portion of the housing 35. The other edge34 b at the rear side of the bus bar 34 is disposed in the projectionrib 35 of the rear frame portion. The bus bar 34 is insert molded intothe housing 35 while the one edge 34 a and the other edge 34 b aredisposed in the above described state.

[0057] In order to mount the electric circuit substrate portion 31,planar upper face portions 35 c and 35 d are provided on the projectionribs 35 a and 35 b of the housing 35. A planar portion 5 e for beingattached the lid 36 formed of resin material to is molded on an upperface portion with opening in the housing 35. The heat radiating plate 46made of a metal material having high heat conductivity is installed onthe back face of the housing 35.

[0058] In the front frame portion 35 a side of this housing 35, the lid36 attached on the upper face portion with opening in the housing 35 isgreatly formed to protrude from the front frame portion 35 a and theheat radiating plate 46 installed on the back face of the housing 35 isgreatly formed to protrude from the front frame portion 35 a. Whereby, acavity portion is defined, which is surrounded by the front frameportion 35 a of the housing 35, the lid 36 and the heat radiating plate46. The resin material 44 having high heat conductivity is poured intothis cavity portion, whereby the welded connection portion between theone end 38 a of the core wire 38 for the harness 37 for outsideconnection and the one edge 34 a of the bus bar 34, disposed in thecavity portion is molded of the resin material 44.

[0059] After the electric circuit substrate portion 31 is mounted withinthe housing 36, a land of the board 32 is soldered with the bus bar 34,whereby the electric circuit wiring of the electric circuit substrateportion 31 having electric circuits including a control circuit aredirectly connected via the bus bar 34 and the harness 37 for outsideconnection to the power supply wiring portion (not shown) such as anexternal battery and the load wiring portion (not shown).

[0060] By placing the welded connection portion between the one end 38 aof the core wire 38 for the harness 37 for outside connection and theone edge 34 a of the bus bar 34 in the cavity portion surrounded by thefront frame portion 35 a of the housing 35, the lid 36 and the heatradiating plate 46 and injection molding the resin material 44 havinghigh heat conductivity, the harness 37 for outside connection weldedwith one edge 34 a of the bus bar 34 has a stronger holding power andthe heating of the welded portion due to supply of large electric powercan be radiated via the resin material 44 to the heat radiating plate46. The cavity portion into which the resin material 44 is filled maybedefined by providing the projection portions on the upper and lowerfaces of the front frame portion 35 a in the housing 35 and molding thefront frame portion having a U-character shape in cross section. Theheat radiating plate 46 may be dispensed with depending on the degree ofheating due to supply of electric power, and the frame portion on thelower face may be integrated with the housing 35. Also, the resinmaterial 44 may not have high heat conductivity.

[0061] The cavity portion surrounded by the front frame portion 35 a ofthe housing 35, the lid 36 and the heat radiating plate 46 may not beprovided depending on the degree of heating due to supply of electricpower. The resin material 44 may not be filled by injection.

[0062] At one edge on the front face side, the bus bar 34 has the oneedge 34 a formed in the L shaped, which the core wire 38 of the harness37 for outside connection is abutted with in advance and is welded toconnect to. A terminal 34 c formed by punching and bending a part of thebus bar 34 is provided at a position facing to a lead wire 45 a of anelectronic component 45 that is spaced a certain length from this oneedge 34 a to the rear face side. A terminal 34 b formed by punching andbending a part of the bus bar 34 is provided at a position facing to theland of the board 32 that is spaced a certain length from this one edge34 a to the rear face side. The bus bar 34 is made of a metal materialsuch as copper and shaped like a plate.

[0063] This bus bar 34 is disposed such that the one edge 34 a of thebus bar 34 projects from the front frame portion 35 a of the housing 35and the portion 34 d spaced from the one edge 34 a of the bus bar 34toward the rear face side penetrate through the projection rib 35 aprovided in the front frame portion of the housing 35. The other end 34e of the bus bar 34 on the rear face side being disposed in theprojection rib 35 b provided in the rear frame portion of the housing35. The bus bar 34 is insert molded into the housing 35 in the abovedescribed state. This bus bar 34 has the lead wire 45 a of theelectronic part 45 having large heat capacity soldered beforehand withthe terminal 34 c of the bus bar 34.

[0064] This housing 35 has the heat radiating plate 46 installed on theback face of the housing 35, and the electronic part 45 having largeheat capacity soldered with the bus bar 34 is attached on the inner faceof this heat radiating plate 46 and fixed by the attaching screw (notshown). After the electric circuit substrate portion 31 is mounted inthe housing 35, the terminal 34 b of the bus bar 34 is soldered with ajoint portion 41 of the land of the board 32, and the power supplywiring is connected via the harness 37 for outside connection and thebus bar 34 to the electric circuit substrate portion 31.

[0065] The harness 37 for outside connection has a jacket 39 ofinsulating material covering the core wire 38 such as copper wire, andis used to make the electrical connections, namely, to connect thewiring of the electric circuit substrate portion 31 having electriccircuits including a control circuit via the bus bar 34 to the powersupply wiring portion (not shown) such as an external battery and theload wiring portion (not shown), to supply a large current to theelectric circuit substrate portion 31. In this harness 37 for outsideconnection, the core wire portion 38 a from which the jacket 39 isremoved at one end of the harness 37 by a predetermined length is weldedbeforehand with the one edge 34 a of the bus bar 34 formed in the Lshaped. The bus bar 37 is bent at a position spaced a certain distancefrom the welded connection portion to be connected to the power supplywiring portion such as external battery and the load wiring portion.

[0066] The welded connection portion between the one end 38 a of thecore wire for the harness 37 for outside connection and the one edge 34a of this bus bar 34 is placed in the cavity portion surrounded by thefront frame portion 35 a of the housing 35, the lid 36 and the heatradiating plate 46. The resin material 44 having high heat conductivityis filled into this cavity portion. Whereby, the harness 37 for outsideconnection welded with one edge 34 a of the bus bar 34 is molded ofresin and has a stronger holding power and the heating of the weldedportion due to supply of large electric power can be radiated via theresin material 44 to the heat radiating plate 46. Since the electronicapparatus is connected to the external battery without using theconnector, it is possible to prevent a current loss in the connectorportion when supplying large current.

[0067] Referring to FIG. 5, a procedure for the wiring connection methodof the wiring connection structure 30 for connecting the electronicapparatus to the outside will be described below.

[0068]FIG. 5 is an explanatory cross-sectional view showing the steps ofthe wiring connection method for connecting the wiring of the electronicapparatus to the outside according to the second embodiment of theinvention. FIG. 5A shows a step of welding the bus bar and the harness.FIG. 5B shows a step of placing the bus bar in the housing in a statewhere the bus bar and the harness are welded. FIG. 5C shows a step ofinsert molding the bus bar and the harness into the housing by fillingresin into the housing. FIG. 5D shows a step of mounting the electriccircuit substrate portion in the housing, soldering the bus bar with thecircuit pattern of the electric circuit substrate portion, and pouringand molding the resin into the welded connection portion between the busbar and the harness.

[0069] In the step of welding the bus bar 34 and the harness 37, severalharnesses 37 for outside connection having a certain length (e.g.,length from a position of one edge 34 a of the bus bar 34 provided inthe electric circuit substrate portion 31 including the control circuitto a position of the power supply wiring portion such as an externalbattery, or to a position of the load wiring portion) are connected withthe bus bar 34 by ultrasonic welding or resistance welding, as shown inFIG. 5A.

[0070] For this connection, the core wire 38 for the harness 37 foroutside connection from which the jacket 39 is removed by apredetermined length is contacted and welded with the one edge 34 a ofthe bus bar 34. Also, the lead wire 45 a of the electrical part 45having large heat capacity is soldered with the projection portion 42 ofthe terminal 34 c of this bus bar 34.

[0071] In the step of placing the bus bar 34 in the housing 35 in astate where the bus bar 34 and the harness 37 are joined, the bus bar 34is disposed in the housing 35 while the welded connection portionbetween the bus bar 34 and the harness 37 protrudes from the front frameportion 35 a of the housing 15, as shown in FIG. 5B. This is performedby placing the rear end portion 34 d of the bus bar 34 in a notchportion 35 g of the projection rib 35 b provided in the rear frameportion of the housing 35 and placing the portion 34 d of the bus bar 34spaced a certain length from the front end portion 34 a toward the rearface side in a notch portion 35 f of the projection rib 35 a provided inthe front frame portion of the housing 35.

[0072] Next, in the step of insert molding the-bus bar 34 and theharness 37 into the housing 35 by filling resin into the housing 35, thebus bar 34 and the harness 37 are insert molded into the housing 35 byfilling resin into a placement portion of the housing 35 where the busbar 34 and the harness 37 are disposed, as shown in FIG. 5C. This isperformed by filling a resin material 46 into the rear end portion 34 eof the bus bar 34 disposed in the notch portion 35 g of the projectionrib 35 b provided in the rear frame portion of the housing 35, andfilling a resin material 47 into the portion 34 d of the bus bar 34spaced a certain length from the front end portion 34 a of the bus bar34 toward the rear face side of the bus bar 34 disposed in the notchportion 35 f of the projection rib 35 a provided in the front frameportion of the housing 35.

[0073] Lastly, in the step of mounting the electric circuit substrateportion 31 in the housing 35 and soldering the bus bar 34 with thecircuit pattern of the electric circuit substrate portion 31 and thestep of pouring and molding the resin material into the weldedconnection portion between the bus bar 34 and the harness 37, the heatradiating plate 46 is installed on the rear face side 35 h of thehousing 35, into which the bus bar 34 welded with the harness 37 foroutside connection is insert molded, and the electric circuit substrateportion 31 is mounted on the upper faces 35 c and 35 d of the projectionribs 35 a and 35 b in the housing 35, as shown in FIG. 5D.

[0074] When installing this heat radiating plate 46 on the rear face 35h of the housing 35, the electric part having large heat capacitysoldered with the bus bar 34 is attached on the inner face of the heatradiating plate 46 using an attaching screw (not shown), after the heatradiating plate 46 is fixed onto the housing 35. At the time of mountingthe electric circuit substrate portion 31 in the housing 35, the endportion 34 b of the bus bar 34 is inserted into the bore 32 b having theland of the board 32 and the electric circuit substrate portion 31 isattached on the housing 35 using an attaching screw (not shown). Theprojection portion 41 at the terminal 34 b of the bus bar 14 insertedinto the bore 32 b having the land of the board 32 and the land of theboard 32 are soldered. This step of soldering the terminal 34 b of thebus bar 34 and the land of the board 32 may be made at the time ofjoining the bus bar 34 and the harness 37 for outside connection beforeplacing the bus bar 34 and the harness 37 for outside connection in thehousing 35.

[0075] Then, the lid 36 is put on the housing 35 having the electriccircuit substrate portion 31 mounted. The resin material 44 having highheat conductivity is poured and molded into the welded connectionportion between the one edge 34 a of the bus bar 34 disposed in thecavity portion surrounded by the front frame portion 35 a of the housing35, the lid 36 and the heat radiating plate 46 and the core wire portion38 a of the harness 37 for outside connection.

[0076] The harness 37 for outside connection disposed in this electronicapparatus is connected to the power supply wiring portion such as anexternal battery (e.g., connected to a connector or a terminal portionof the battery) and the load wiring portion (e.g., a wiring portion onthe board making up a load circuit or a load circuit connector).

[0077] In the case where the cavity portion into which the resinmaterial 44 is filled is formed by providing the projection portions onthe upper and lower faces of the front frame portion 35 a in the housing35, and molding the front frame portion having a cross section of theU-character shape, the step of pouring the resin material 44 having highheat conductivity into the cavity portion may be made in the step ofinsert molding the bus bar welded with the harness into the housing byfilling the resin in the housing, as shown in FIG. 5C. In the secondembodiment of the invention, the bus bar 34 is insert molded into thehousing 35 in a state where the one edge 34 a of the bus bar 34 and thecore wire 38 of the harness 37 for outside connection are welded and thewelded connection portion between the one edge 34 a of the bus bar 34and the core wire 38 of the harness 37 for outside connection is moldedof the resin material 44. Alternatively, the bus bar 34 may be insertmolded into the housing 35, and then one edge 34 a of the bus bar 34 andthe core wire 38 of the harness 37 for outside connection may besoldered, whereby the welded connection portion between the one edge 34a of the bus bar 34 and the core wire 38 of the harness 37 for outsideconnection may be molded of the resin material 44. Also, in the secondembodiment of the invention, the bus bar 34 welded with the core wire 38of the harness 37 for outside connection is insert molded into thehousing 35 and then the welded connection portion is molded of the resinmaterial 44. Alternatively, the bus bar 34 and the welded connectionportion may be insert molded into the housing 35 in the same step sothat the resin material 44 and the front frame portion 35 a of thehousing 35 may be integrated.

[0078] As described above, in the wiring connection method and thewiring connection structure 30 for connecting the electronic apparatusto the outside according to the second embodiment of this invention, thebus bar 34 used to supply a large current and the harness 37 for outsideconnection are welded and the bus bar 34 is insert molded into thehousing 35 for the electronic apparatus in a state where they are joinedto each other, and the harness 37 for outside connection welded with thebus bar 34 is molded of the resin material 44 having high heatconductivity. Whereby the wiring of the electric. circuit substrateportion 31 having electric circuits including a control circuit, whichis soldered to the bus bar 34, to the outside can be directly connectedvia the harness 37 for outside connection to the power supply wiringportion such as an external battery and the load wiring portion withoutthe use of any connector. Hence, number of parts such as a connector canbe reduced. Since the bus bar 34 and the harness 37 for outsideconnection are joined before being accommodated within the housing 35,number of steps for soldering the connector pin and the bus bar can bereduced. Since the welded portion between the harness 37 for outsideconnection and the bus bar 34 is molded of the resin material 44 havinghigh heat conductivity, the heat generated in the welded connectionportion between the harness 37 for outside connection and the bus bar 34due to a large current applied can be diffused via the resin material 44to the heat radiating plate 46, and the harness 37 for outsideconnection has a stronger holding power.

[0079] A wiring connection structure 50 for connecting an electronicapparatus to the outside according to a third embodiment of theinvention will be described below with reference to the accompanyingdrawings.

[0080]FIG. 6 is a cross-sectional view showing the wiring connectionstructure for connecting the wiring of the electronic apparatus to theoutside according to the third embodiment of the invention. FIG. 6A is aperspective view, partly in cross section, and FIG. 6B is across-sectional view.

[0081] The wiring connection structure 50 for connecting the electronicapparatus to the outside according to the third embodiment of theinvention, in contrast to the first embodiment of the invention,includes a harness 57 for outside connection formed of a core wire 58made of metal wire rod such as copper wire having a jacket 59 made of aninsulating material to supply a large current within the housing,without using a bus bar, in which the harness 57 for outside connectionis laid to face connection with an electric circuit substrate portion 51and directly insert molded into a front frame portion 55 a and a rearframe portion 55 b in the housing 55, as shown in FIG. 8. This insertmolding is made by disposing a rear face end portion 57 b of the harness57 for outside connection within the rear frame portion 55 b and placinga front lead-out portion 57 a of the harness 57 for outside connectionto penetrate through the front frame portion 55 a, in which one end ofthe harness 57 for outside connection insert molded into the housing 55is soldered with a terminal of the electric circuit substrate portion51. Accordingly, only a different point from the first embodiment of theinvention will be described. The different point includes injectionmolding the harness 57 for outside connection into the housing 55. Thedescription of other points is omitted.

[0082] The housing 55 is formed of resin material such as ABS resin andshaped like a box, in which the harness 57 for outside connection formedof a metal wire rod such as copper wire having the jacket made of aninsulating material is insert molded into the housing 55. Within thishousing 55, the electric circuit substrate portion 51 is mounted, and alid 56 formed of resin material is attached on the upper face side-ofthe housing 55.

[0083] The projection ribs 55 a and 55 b are provided on the inner facesof the front frame portion 55 a and the rear frame portion 55 b for thishousing 55, respectively. The harness 57 for outside connection isinsert molded in such a manner that within a projection rib 55 a of thisfront frame portion, a front face lead-out portion 57 a of the harness57 for outside connection is disposed to penetrate through theprojection rib 55 a in a state where the jacket 59 covers the core wire58, and a rear face end portion 57 b of the harness 57 for outsideconnection is disposed within a projection rib 55 b. The planes formounting the electric circuit substrate portion 51 are provided on theupper faces 55 c and 55 d of the projection ribs 55 a and 55 b in thehousing 55, and a planar portion 55 e for being attached the lid 56formed of resin material to is molded on an upper face portion withopening in the housing 55.

[0084] After the electric circuit substrate portion 51 is mounted withinthe housing 55, the land of the board 52 is soldered with one end 58 aof the core wire 58 for the harness 57 for outside connection, wherebythe electric circuit wiring of the electric circuit substrate portion 51having electric circuits including a control circuit are directlyconnected via the harness 57 for outside connection to a power supplywiring portion (not shown) such as an external battery and a load wiringportion (not shown).

[0085] The harness 57 for outside connection has the jacket 59 ofinsulating material covering the core wire 58 such as copper wire, andis used to make the electrical connections, particularly to connect theelectric circuit wiring of the electric circuit substrate portion 51having electric circuits including a control circuit via the harness 57for outside connection to the power supply wiring portion (not shown)such as an external battery and the load wiring portion (not shown), tosupply a large current to the electric circuit substrate portion 51.

[0086] This harness 57 for outside connection has the front facelead-out portion 57 a of the harness 57 for outside connection disposedto penetrate through the projection rib 55 a of the housing 55 in astate where the jacket 59 covers the core wire 58 and the rear face endportion 57 b of the harness 57 for outside connection placed within theprojection rib 55 b of the housing 55. In the above described state, theharness 57 is insert molded. The harness 57 for outside connectioninsert molded into this housing 55 is laid a certain length from thefront face lead-out portion 57 a and connected to the power supplywiring portion such as external battery and the load wiring portion.

[0087] For this harness 57 for outside connection, after the electriccircuit substrate portion 51 is mounted in the housing 55, one end ofthe harness 57 is bent in a direction against the electric circuitsubstrate portion 51, the core wire 58 a from which the jacket 59 isremoved by a certain length is inserted into the bore 52 b having theland on the electric circuit substrate portion 51 to project from theelectric circuit substrate portion 51, in which the core wire 58 a ofthe projecting portions 61 b and 61 a is soldered with the land, and thepower supply wiring is connected to the land of the board 52, directlyusing the harness 57. Whereby, the harness 57 for outside connection isinsert molded into the housing 55 with a stronger holding power, and canbe directly connected to the external battery without the use of any busbar and any connector, it is possible to prevent a current loss in thebus bar and the connector portion when supplying large current, andenhance the quality.

[0088] Next, a procedure for the wiring connection method of the wiringconnection structure 50 for the electronic apparatus to the outside willbe described below. Several harnesses 57 for outside connection having acertain length (e.g., length from a position of the electric circuitsubstrate portion 51 including the control circuit to a position of thepower supply wiring portion such as an external battery, or to aposition of the load wiring portion) are insert molded into the housing55. In this insert molding, the front face lead-out portion 57 a of theharness 57 for outside connection is disposed to penetrate through theprojection rib 55 a of the housing 55 in a state where the jacket 59covers the core wire 58 and the rear face end portion 57 b of theharness 57 for outside connection is disposed within the projection rib55 b of the housing 55. After the electric circuit substrate portion 51is mounted on the upper faces 55 c and 55 d of the projection ribs 55 aand 55 b in the housing 55, one end of the harness 57 is bend in adirection against the electric circuit substrate portion 51, and thecore wire 58 a from which the jacket 59 is removed a predeterminedlength is inserted into the bore 52 b having the land on the electriccircuit substrate portion 51 to project from the electric circuitsubstrate portion 51. Whereby the core wire 58 a of the projectingportions 61 b and 61 a is soldered with the land. The lid 56 is put onthe housing 55, and an electric apparatus of closed structure, forexample, is assembled. Also, the harness 57 for outside connectioninsert molded into this housing 55 is laid a certain length from thefront face lead-out portion 57 a, and connected to the power supplywiring portion such as external battery and the load wiring portion.

[0089] As described above, in the wiring connection method and thewiring connection structure 50 for connecting the electronic apparatusto the outside according to the third embodiment of the invention, theharness 57 for outside connection is directly insert molded into thehousing 55, without providing the bus bar to supply large current, oneend of the harness 57 for outside connection within the housing 55 beingsoldered to the terminal of the electric circuit substrate portion 51,and the harness 57 for outside connection is connected to the powersupply wiring portion such as external battery and the load wiringportion, whereby the number of parts such as bus bar and connector canbe reduced, and no step for soldering the bus bar and the connector pinis required, because of no use of the bus bar, resulting in lower costs.Moreover, it is possible to prevent a current loss due to the bus barand the connector portion when supplying large current, and enhance thequality. Since the harness 57 for outside connection is insert moldedinto the housing 55, the harness 57 for outside connection has astronger holding power.

[0090] As described above, with the present invention, the number ofjoining steps can be reduced by joining the bus bar and the harnessbefore accommodating them within the housing. Also, the costs can be cutback by removing the wiring connection between the connector and the busbar without using the connector. A current loss due to the connectorportion is prevented even if a large current is applied, and the heatingat the junction portion with the connector is diffused, whereby thequality can be improved.

What is claimed is:
 1. A wiring connection method comprising the stepsof: connecting a bus bar for wiring inside an electronic apparatus and aharness for leading out wiring to outside; placing the bus bar and theharness connected together on a notch portion of a housing; and fillinga resin to fix the harness in the notch portion of the housing.
 2. Thewiring connecting method according to claim 1, wherein in the placingstep, a connection portion between the bus bar and the harness is placedin a portion to be filled with the resin.
 3. The wiring connectingmethod according to claim 1, wherein in the filling step, a connectionportion between the bus bar and the harness is covered with the resin.4. The wiring connecting method according to claim 2, further comprisingthe steps of disposing a heat sink to contact with a portion filled withthe resin.
 5. The wiring connecting method according to claim 1, furthercomprising the steps of soldering the bus bar with an electric circuitboard.
 6. A wiring connection method comprising the steps of: connectinga bus bar for wiring inside an electronic apparatus and a harness forleading out wiring to outside; placing the bus bar and the harness on anotch portion of a housing so that a connecting portion between the busbar and the harness is exposed outside the housing; filling a resin tofix the bus bar in the notch portion of the housing to insert-mold thebus bar into the housing; and covering the connection portion betweenthe bus bar and the harness exposed from the housing with a thermalconductive resin.
 7. A wiring connection method comprising the steps of:placing a bus bar on a notch portion of a housing so that a top endportion of the bus bar for wiring inside an electronic apparatus isexposed outside the housing; filling a resin to fix the bus bar in thenotch portion of the housing to insert-mold the bus bar into thehousing; connecting a harness with the bus bar at the outside of thehousing; and covering a connection portion between the bus bar and theharness exposed from the housing with a thermal conductive resin;wherein the placing step is conducted prior to the connecting step.
 8. Awiring connection method for an electronic apparatus containingelectronic parts requiring large current for driving, the methodcomprising the steps of integrally molding a harness for wiring insidethe electronic apparatus and leading out wiring to outside of a housingwith the housing at a time of molding the housing.
 9. The wiringconnection method according to claim 8, further comprising the steps ofplacing the harness on a notch portion of the housing.
 10. A wiringconnection structure for an electronic apparatus containing electronicparts requiring large current for driving, the structure comprising: ahousing; and a harness for wiring inside the electronic apparatus andleading out wiring to outside of the housing; wherein the harness ismolded integrally with a housing.
 11. The wiring connection structureaccording to claim 10, wherein a notch portion is formed in the housing;wherein the harness passes through the notch portion from outside of thehousing to inside thereof; and wherein the harness has core wiringcovered with a jacket.